Seat-mounted airbag device
A seat-mounted airbag device including an inflator that is provided at a vehicle seat and that ejects gas during a vehicle collision; and an airbag including an airbag body that, by being supplied with gas ejected from the inflator, moves toward a seat front side through between a head of a passenger seated on a vehicle seat and a ceiling of a vehicle cabin, and is expanded and deployed, so as to be disposed at the seat front side of the passenger, wherein the airbag is housed in the headrest with both seat width direction end portions fold-bent toward a seat downward side, so as to follow an external profile of a headrest of the vehicle seat in face-on view seen from the seat front side.
1 . A seat-mounted airbag device comprising:
an inflator that is provided at a vehicle seat and that ejects gas during a vehicle collision; and
an airbag including an airbag body that, by being supplied with gas ejected from the inflator, moves toward a seat front side between a head of a passenger seated on the vehicle seat and a ceiling of a vehicle cabin, and is expanded and deployed, so as to be disposed at the seat front side of the passenger,
wherein the airbag includes the airbag body being packed up in a roll shape rolled from the outside and both seat width direction end portions folded into a concertina shape, and the both seat width direction end portions are fold-bent toward a seat downward side such that the airbag body and the both seat width direction end portions are housed in a headrest so as to follow an external profile of the headrest of the vehicle seat in face-on view seen from the seat front side.
2 . The seat-mounted airbag device of claim 1 , wherein:
the two seat width direction end portions of the airbag are a pair of front-rear chambers that, by being supplied with gas ejected from the inflator, expand and deploy toward the seat front side via both left and right sides of the head of the passenger; and
the airbag body moves toward the seat front side between the head of the passenger and the ceiling as the pair of front-rear chambers are being expanded and deployed, and the airbag body is expanded and deployed toward a seat rear side between the pair of front-rear chambers so as to be disposed at the seat front side of the passenger by being supplied with the gas from the pair of front-rear chambers.
3 . The seat-mounted airbag device of claim 2 , wherein the pair of front-rear chambers are fold-bent toward the seat downward side, from boundary portions with the airbag body.
4 . The seat-mounted airbag device of claim 3 , wherein the headrest is integrally formed with a seatback of the vehicle seat.
5 . The seat-mounted airbag device of claim 4 , wherein left and right airbag doors, that are formed by the headrest rupturing during expansion and deployment of the pair of front-rear chambers, are configured to turn in toward the head of the passenger.
6 . The seat-mounted airbag device of claim 5 , wherein the left airbag door is discontinuous with respect to the right airbag door.
7 . The seat-mounted airbag device of claim 6 , further comprising a top airbag door in the head rest, wherein the top airbag door is separate from each of the left and right airbag doors.
8 . The seat-mounted airbag device of claim 4 , wherein the inflator is a single inflator disposed along an extension direction of the seatback of the vehicle seat, and is configured to eject the gas toward an inside of distribution piping capable of supplying the gas respectively to the pair of front-rear chambers.
9 . The seat-mounted airbag device of claim 8 , wherein ejection ports of the distribution piping, that are connected to basal portions of the pair of front-rear chambers, each extend with a specific length toward a seat width direction outside and forward in plan view.